Vespa Orientalis Research Articles

The presence of statocysts and statoliths in social wasps (hymenoptera, vespinae)

Static sense organs composed of a hollow statocyst surrounded by sensory hairs and containing aggregate bodies (statoliths) have been detected in various species of Vespinae. On the frons in the groove traversing its center (the frontal groove) there is a deep pit and around it a membrane enclosing a cyst-like sac. In Vespa orientalis there are silicon (Si) and calcium (Ca)-containing aggregates inside the pit arranged in morula-like fashion, and in V. crabro , there are similar aggregates arranged in an ear-like shape. In general this sensillar organ resembles the statocyst located on the bases of the antennules in decapod crustaceans.

Combativeness among oriental hornet queens

Queens of the Oriental hornet are aggressive towards one another in the beginning of the active season, during the months of May, June and July: they defend their “Lebenraum” within the nest and do not enable any other queen to enter their territory. At that period any encounter between two queens, whether within the nest of the one or anawhere else, releases mutual aggressive behavior. The ensuing combat may last for hours and in its course, if the one queen beats the other, it stings it to death in the neck. In many instances, however, the combat remains unresolved and the exhausted combatants withdraw to recuperate before resuming their battle. At other times, one of the queens may succeed in maiming its rival by amputating the tips of its limbs at which point the disabled queen concedes the fight by assuming an “inferior” posture towards the victor and making a food offering. The various phases in the combat between queen pairs are described in detail.

Amino acid sequence of an insect chymotrypsin from the larvae of the hornet, Vespa orientalis

The complete amino acid sequence of the endopeptidase II from the larvae of the hornet, Vespa orientalis, has been determined. The enzyme is a single polypeptide chain of 216 residues. The protease is a serine endopeptidase. When aligned for optimal homology to the trypsin related proteases, the insect endopeptidase displays 37% identity with bovine chymotrypsin. The structure of the hornet protease is the first reported for a serine endopeptidase from an insect.

Detection of common antigenic sites in lethal proteins of non-related animal venoms

A. J. Russo, C. S. Cobbs, G. J. Calton and J. W. Burnett. Detection of common antigenic sites in lethal proteins of non-related animal venoms. Toxicon 21, 433–437, 1983. — Monoclonal antibodies neutralizing specific coelenterate lethal toxins were used to determine the presence of homologous antigenic sites on toxin proteins of a rattlesnake ( Crotalus durissus terrificus), a hornet ( Vespa orientalis) and the sea wasp ( Chironex fleckeri). An anti-Portuguese man-o'war toxin antibody was found useful for isolating a C. d. terrificus toxin.

Hypothermia induced in mice by injection of venom sac extract of hornets (Vespa orientalis, vespinae: hymenoptera).

Intraperitoneal injection into naive and immunized albino mice of Oriental hornet venom sac aqueous extract induces within 3 h an 8-10 degrees C and 3-4 degrees C drop in body temperature, respectively. The fall in temperature is dose-dependent. The responsible fraction(s) in the venom is of high molecular weight.

Isolation of a lethal factor from venom of Vespa orientalis (oriental hornet) by affinity chromatography using cross reactive monoclonal antibody

Monoclonal antibody directed against a lethal factor (PLF) of Portuguese man-o'war ( Physalia physalis) nematocyst venom cross-reacted with a component of oriental hornet ( Vespa orientalis) venom in an ELISA. Using immobilized PLF monoclonal antibody, a protein fraction was eluted which was lethal to mice. This fraction (VOLF) contains a major component of molecular weight about 43,000, in addition to several minor components.

Synthesis of the two enantiomeric forms of 5-hexadecanolide proposed pheromone component from Vespa orientalis

The first synthesis of R-(+)-5-hexadecanolide 1 and of it's S isomer 2 has been achieved in 9 steps, from the 4 chiral synthon 3 ; the absolute configuration is determined by conversion of the key intermediates 12 and 13 into R-and S-1,2-heptandiol.

Selective alkylation of diethyl 3-oxoglutarate. Part IX. Synthesis of racemates and (+)-enantiomers of .GAMMA.-caprolactone, .GAMMA.-dodecanolactone and .DELTA.-hexadecanolactone, lactonic sex pheromones of the dermestid beetle, rove beetle and Oriental hornet.

A simple method based on regioselective two-step alkylation of easily-available diethyl 3-oxoglutarate (2) is described for the synthesis of racemates of the lactonic pheromones, la, lb, and 1c. Their (+)-enantiomers were also synthesized by means of microbiological reduction of the intermediary keto acids.

The sounds of honey bees and social wasps are always composed of a uniform frequency

The sounds produced by the honeybee Apis mellifera (Apidae) and by the social wasps Paravespula germanica and Vespa orientalis (Hymenoptera, Vespinae) are of a uniform frequency which nevertheless differs in accordance with its purpose. In honey bees, the sound produced by ventilating workers has a frequency of 309 Hz, whereas that produced by the queen (queen piping) has a frequency of 450 Hz. In P. germanica, the sound frequency during ventilation is 194–231 Hz, whereas in V. orientalis, the ventilation and the awakening dance sounds (produced by the workers) and the hunger signal (sounded by the larvae) have a frequency of 118–140 Hz, while the threatening flight occurs at 221 Hz and the dance of workers facing the queen—at 600–637 Hz. All the produced sounds are synchronized to a uniform frequency over a given period, regardless of whether they are produced by a single insect or by an entire group. However, the frequency may change with time, probably owing to fatigue of the producer, and also the intensity of the sound may change, which results in a great variability of the sounds despite their uniform frequency.

Severe late clinical manifestations after hornet (Vespa orientalis) stings-in a young child

Severe late clinical manifestations after hornet (Vespa orientalis) stings-in a young child

Changes in the Yellow Pigment of the Oriental Hornet, Vespa orientalis, Induced by Aging, Mutations and Allopurinol (Hymenoptera: Vespidae)

Changes in the Yellow Pigment of the Oriental Hornet, Vespa orientalis, Induced by Aging, Mutations and Allopurinol (Hymenoptera: Vespidae)

Temperature dependence of the electric resistivity of the hornet cuticle

Resistance to electricity of the oriental hornet cuticle is temperature dependent. Evidence is provided to suggest that this electric resistance and its organic semiconductor-like behaviour are possibly interconnected with temperature detection by hornets.

Proteins in venoms of two wasps, Polistes comanchus navajoe and Vespa orientalis

1. By means of gel electrophoresis the basic proteins in venoms of Polistes comanchus navajoe and Vespa orientalis were resolved into 6 and 5 proteins respectively, all of molecular weights >15,000. 2. Several proteins appeared to be similar in both venoms. 3. The main component of P. comanchus venom responsible for hemolysis was isolated, and data concerning its thermolability, molecular weight (approximately 26,000) and amino acid composition show that unlike the cytolytic components of bee and ant venoms which are small peptides, the corresponding functional entity of P. comanchus venom (polistin) is a protein having the characteristics of an enzyme.

Temperature-dependent electrical resistivity of the hornet cuticle: Changes induced by colchicine and purine in the diet

Various cuticular areas of the Oriental hornet ( Vespa orientalis) were measured for their electrical resistivity within the range of 3–40°C. It was found that: (1) the electrical resistivity is temperature dependent; (2) there are no significant differences in this respect between hornets collected in different regions; (3) there are no differences in the electrical resisitivity between the yellow and brown areas of the cuticle in control hornets; (4) there are however, significant changes in resistance between the yellow and brown strips of hornets fed on purine; (5) hornets fed on colchicine reach a minimum resistance at a higher temperature than do the control hornets; and (6) hornets fed on purine reach a minimum resistance at a lower temperature. It is suggested that the cuticular changes in resistivity at different temperatures reflect the hornets' mechanism of detecting and adjusting to changes in the ambient temperature.

Temperature dependence of the electrical resistivity of social wasp cuticle: A comparative study

Resistance to electricity by social wasp cuticle is temperature dependent within the range of 1–40°C. This was measured on the species Vespa orientalis (the Oriental hornet), Vespa crabro (the European hornet) and the wasp Dolichovespula saxonica. The resistance at first decreases with increased temperature, reaching a nadir which differs according to species, and then rises again up to 40°C, the highest temperature tested. It is suggested that the cuticular changes in resistivity at different temperatures reflect the wasp's mechanism for detecting and regulating the temperature in their normal environment.

Thermoelectric (seebeck) effect of the cuticle of social wasps

The thermoelectric (Seebeck) coefficient ( S = ΔV ΔT ) in various cuticular areas of the Oriental hornet ( Vespa orientalis) fluctuates from 0·3 to 2·4 mV deg −1 within a temperature range of 27–36°C and when the temperature difference between the two measuring electrodes (Δ T) is 0·6–8·0°C. The values measured on the brown-colored cuticle suggest an n-type conduction, while those measured on the yellow-colored cuticle point to a p-type conduction. It is suggested hornets use this phenomenon for temperature detection.

Comparison of biochemical and immunologic properties of venoms from four hornet species

Venoms of two American hornets, Vespula maculata (bald-faced hornet) and Vespula arenaria (yellow hornet), and two Old World hornets, Vespa crabro and Vespa orientalis, were investigated for biochemical and immunologic properties. They were similar with regard to enzymatic activities (phospholipase A, phospholipase B, and hyaluronidase) and molecular composition. Analysis of radioallergosorbent test (RAST) results obtained from 30 vespid-sensitive patients suggests extensive cross-reactivity between the venoms of V. arenaria, V. maculata, and V. crabro, but the venom of V. orientalis seems to lack at least one important allergen. Rabbit antisera to each of the four venoms contain precipitating antibodies to all four venoms. Strong cross-reactivity was found between the venoms of V. maculata, V. arenaria, and V. crabro and between V. crabro and V. orientalis. V. orientalis venom cross-reacts weakly with the venoms of both V. maculata and V. arenaria. It is concluded therefore that diagnosis and immunotherapy with commercially available venoms of V. maculata and V. arenaria should be adequate for most patients sensitive to V. maculata, V. arenaria, or V. crabro but probably not for a significant proportion of those individuals primarily sensitive to V. orientalis.

The amino acid sequences around the reactive serine and histidine residues of the chymotrypsin-like protease from the hornet, Vespa orientalis

The endopeptidase II from the larva of the hornet Vespa orientalis was inactivated by radioactively labeled active-site-directed inhibitors and afterwards digested with trypsin and chymotrypsin. The labeled peptides were isolated and sequenced. The peptide around the reactive serine residue contains 39 amino acids, and 30 amino acids constitute the peptide around the essential histidine residue. These peptides show sequence homology to the corresponding ones of the trypsin-related endopeptidases.

Effects of xanthines and colchicine on the longevity, photoconductive properties and yellow pigment structure of the oriental hornet Vespa Orientalis L.

In one experiment xanthines and colchicine were fed to adult Oriental hornets collected at random from nests in the field. Arranged by their effect on hornet longevity, the drugs are as follows: colchicine, hypoxanthine, adenine, control group, 2,3-diaminopyridine, xanthine, 2-aminopyrimidine, theobromine, allopurinol, 4,5-diaminopyrimidine and theophylline. Hornets fed on the last 3 compounds mentioned had a significantly longer life-span than the cotnrol group. Allopurinol and theophylline have a considerable life-prolonging effect and preserve the electric properties of the cuticle, but differ in their effect on the structure of the yellow pigment crystals; those of theophylline remain intact, while those of allopurinol are enlarged and start to degenerate. In a second experiment juvenile Oriental hornets were reared in the laboratory since eclusion. The hornets were found to live longer in daylight than under constant artificial illumination and in groups of 10 than in groups of 40 individuals. Additionally, when fed on colchicidine, purine or caffeine the juvenile hornets survived for a very brief period but when fed caffeine together with colchicine or purine together with colchicine, albeit shorter-lived than in control hornets, they lived longer than those on colchicine or purine alone. The purine changes the photoconductive properties of the yellow strips in the hornet cuticle. Colchicine, in addition, caused drastic changes in the structure of the yellow pigment within the cuticle. However, when the 2 compounds were given together or the colchicine was given with caffeine, there were no marked changes in the properties or structure of the pigment crystals.

A neutral DNase in venom sac extract of the oriental hornet Vespa orient alis: Characterization, specificity and mode of action

A neutral DNase was purified by acrylamide gel electrophoresis from venom sac extracts of the Oriental hornet ( Vespa orientalis). The DNase is active optimally at pH 7 in 0·05 M Tris-HCl buffer. Addition of NaCl inhibited the DNase activity, and with 0·15 M NaCl the enzyme was completely inhibited. RNA addition also inhibited the enzyme activity. Divalent cations were essential for enzymatic activity. At 1 mM concentrations, MgCl 2 was the best activator while MnCl 2 and CaCl 2 activations were, respectively, about 75% and 25% that of the magnesium salt. EDTA completely inhibited DNase activity. The DNase was characterized as an endonuclease by its ability to nick circular supercoiled PM2 DNA. It is equally active on both native and single-stranded DNA as substrates and produces oligonucleotides terminated by 5′ phosphate and 3′ hydroxyl groups. The enzyme is free of RNase and of non-specific phosphodiesterase activities.